The majority of present day integrated circuits (ICs) are implemented by using a plurality of interconnected field effect transistors (FETs), also called metal oxide semiconductor field effect transistors (MOSFETs or MOS transistors). A MOS transistor includes a gate electrode as a control electrode overlying a channel of a semiconductor substrate. Spaced-apart source and drain regions are in the substrate on opposite sides of the channel, and current can flow between the source and drain within the channel. A gate insulator is disposed between the gate electrode and the channel of the semiconductor substrate to electrically isolate the gate electrode from the substrate. A control voltage applied to the gate electrode controls the flow of current through the channel between the source and drain regions.
There are many processes used in the manufacture of integrated circuits, and one of those processes that may be used is plasma induced ion bombardment. Plasma induced ion bombardment can produce an accumulation of trapped ions in a back gate area underlying a transistor gate at the interface of a semiconductor layer and a buried oxide layer (BOX layer) in a silicon-on-insulator (SOI) type substrate, especially in back end of the line processes. The SOI substrate includes a handle layer under the BOX layer. The accumulation of trapped ions produces a charge that can damage the back gate area, especially if the handle layer has a high resistivity. High resistivity handle layers can improve antenna performance in integrated circuits that use radio waves, so SOI substrates with high resistivity handle layers are employed for some integrated circuits.
Accordingly, it is desirable to provide methods of producing integrated circuits that reduce or eliminate back gate damage during plasma induced ion bombardment, and integrated circuits produced by such methods. In addition, it is desirable to provide integrated circuits that can drain a charge accumulation at the back gate area without inducing excessive currant leakage, and methods of producing the same. Furthermore, other desirable features and characteristics of the present embodiment will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.